kolibrios-gitea/kernel/branches/kolibri_pe/include/atomic.h

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/*
* Copyright (c) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef KERN_ATOMIC_H_
#define KERN_ATOMIC_H_
typedef struct atomic {
volatile long count;
} atomic_t;
static inline void atomic_inc(atomic_t *val) {
#ifdef USE_SMP
asm volatile ("lock incl %0\n" : "+m" (val->count));
#else
asm volatile ("incl %0\n" : "+m" (val->count));
#endif /* USE_SMP */
}
static inline void atomic_dec(atomic_t *val) {
#ifdef USE_SMP
asm volatile ("lock decl %0\n" : "+m" (val->count));
#else
asm volatile ("decl %0\n" : "+m" (val->count));
#endif /* USE_SMP */
}
/*
static inline long atomic_postinc(atomic_t *val)
{
long r = 1;
asm volatile (
"lock xadd %1, %0\n"
: "+m" (val->count), "+r" (r)
);
return r;
}
static inline long atomic_postdec(atomic_t *val)
{
long r = -1;
asm volatile (
"lock xadd %1, %0\n"
: "+m" (val->count), "+r"(r)
);
return r;
}
#define atomic_preinc(val) (atomic_postinc(val) + 1)
#define atomic_predec(val) (atomic_postdec(val) - 1)
static inline u32_t test_and_set(atomic_t *val) {
uint32_t v;
asm volatile (
"movl $1, %0\n"
"xchgl %0, %1\n"
: "=r" (v),"+m" (val->count)
);
return v;
}
*/
/* ia32 specific fast spinlock */
static inline void atomic_lock_arch(atomic_t *val)
{
u32_t tmp;
// preemption_disable();
asm volatile (
"0:\n"
"pause\n" /* Pentium 4's HT love this instruction */
"mov %0, %1\n"
"testl %1, %1\n"
"jnz 0b\n" /* lightweight looping on locked spinlock */
"incl %1\n" /* now use the atomic operation */
"xchgl %0, %1\n"
"testl %1, %1\n"
"jnz 0b\n"
: "+m" (val->count), "=&r"(tmp)
);
// CS_ENTER_BARRIER();
}
static inline void atomic_set(atomic_t *val, long i)
{
val->count = i;
}
static inline long atomic_get(atomic_t *val)
{
return val->count;
}
#endif /* KERN_ATOMIC_H_ */